The Experts below are selected from a list of 119748 Experts worldwide ranked by ideXlab platform
Rajesh Khare - One of the best experts on this subject based on the ideXlab platform.
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cross stream chain migration in nanofluidic Channels effects of chain length Channel height and chain concentration
Journal of Chemical Physics, 2009Co-Authors: Swapnil C. Kohale, Rajesh KhareAbstract:We use molecular dynamics simulations to study the shear flow of a polymer solution in a nanoChannel by using an explicit, atomistic model of the solvent. The length scales representing the chain Size, Channel Size, and the molecular scale structure in these nanoChannels are comparable. The diffusion and hydrodynamic interactions in the system are governed by the intermolecular interactions in the explicit solvent model that is used in the simulations. We study the cross stream migration of flexible polymer chains in a solution that is subjected to a planar Couette flow in a nanoChannel. We present a detailed study of the effects of chain length, Channel Size, and solution concentration on the cross stream chain migration process. Our results show that when a dilute solution containing a longer and a shorter chain is subjected to shear flow, the longer chains that are stretched by the flow migrate away from the Channel walls, while the shorter chains that do not stretch also do not exhibit this migration ...
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cross stream chain migration in nanofluidic Channels effects of chain length Channel height and chain concentration
Journal of Chemical Physics, 2009Co-Authors: Swapnil C. Kohale, Rajesh KhareAbstract:We use molecular dynamics simulations to study the shear flow of a polymer solution in a nanoChannel by using an explicit, atomistic model of the solvent. The length scales representing the chain Size, Channel Size, and the molecular scale structure in these nanoChannels are comparable. The diffusion and hydrodynamic interactions in the system are governed by the intermolecular interactions in the explicit solvent model that is used in the simulations. We study the cross stream migration of flexible polymer chains in a solution that is subjected to a planar Couette flow in a nanoChannel. We present a detailed study of the effects of chain length, Channel Size, and solution concentration on the cross stream chain migration process. Our results show that when a dilute solution containing a longer and a shorter chain is subjected to shear flow, the longer chains that are stretched by the flow migrate away from the Channel walls, while the shorter chains that do not stretch also do not exhibit this migration behavior. The thickness of the chain depletion layer at the Channel surface resulting from cross stream migration is found to increase with an increase in the Channel height. On the other hand, this degree of migration away from the Channel walls is found to decrease with an increase in the solution concentration. In solutions with concentrations comparable to or greater than the overlap concentration, the depletion layer thickness in shear flow is found to be comparable or slightly smaller than that observed in the absence of flow.
David A. Wharam - One of the best experts on this subject based on the ideXlab platform.
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few electron limit of n type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Marco Michielis, Simone Cocco, Marco Fanciulli, Dieter P. Kern, Dharmraj Kotekarpatil, David A. WharamAbstract:We report the electronic transport on n-type silicon single electron transistors (SETs) fabricated in complementary metal oxide semiconductor (CMOS) technology. The n-type metal oxide silicon SETs (n-MOSSETs) are built within a pre-industrial fully depleted silicon on insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 × 20 nm(2) is obtained by employing electron beam lithography for active and gate level patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a current spin density functional theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronic and quantum variable based devices.
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Few electron limit of n-type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Dharmraj Kotekar-patil, Marco Michielis, Simone Cocco, David A. Wharam, Marco Fanciulli, Dieter P. Kern, Jan VerduijnAbstract:We report electronic transport on n-type silicon Single Electron Transistors (SETs) fabricated in Complementary Metal Oxide Semiconductor (CMOS) technology. The n-MOSSETs are built within a pre-industrial Fully Depleted Silicon On Insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 $\times$ 20 nm$^{2}$ is obtained by employing electron beam lithography for active and gate levels patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a Current Spin Density Functional Theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronics and quantum variables based devices.
Marco Fanciulli - One of the best experts on this subject based on the ideXlab platform.
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few electron limit of n type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Marco Michielis, Simone Cocco, Marco Fanciulli, Dieter P. Kern, Dharmraj Kotekarpatil, David A. WharamAbstract:We report the electronic transport on n-type silicon single electron transistors (SETs) fabricated in complementary metal oxide semiconductor (CMOS) technology. The n-type metal oxide silicon SETs (n-MOSSETs) are built within a pre-industrial fully depleted silicon on insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 × 20 nm(2) is obtained by employing electron beam lithography for active and gate level patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a current spin density functional theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronic and quantum variable based devices.
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Few electron limit of n-type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Dharmraj Kotekar-patil, Marco Michielis, Simone Cocco, David A. Wharam, Marco Fanciulli, Dieter P. Kern, Jan VerduijnAbstract:We report electronic transport on n-type silicon Single Electron Transistors (SETs) fabricated in Complementary Metal Oxide Semiconductor (CMOS) technology. The n-MOSSETs are built within a pre-industrial Fully Depleted Silicon On Insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 $\times$ 20 nm$^{2}$ is obtained by employing electron beam lithography for active and gate levels patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a Current Spin Density Functional Theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronics and quantum variables based devices.
Enrico Prati - One of the best experts on this subject based on the ideXlab platform.
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few electron limit of n type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Marco Michielis, Simone Cocco, Marco Fanciulli, Dieter P. Kern, Dharmraj Kotekarpatil, David A. WharamAbstract:We report the electronic transport on n-type silicon single electron transistors (SETs) fabricated in complementary metal oxide semiconductor (CMOS) technology. The n-type metal oxide silicon SETs (n-MOSSETs) are built within a pre-industrial fully depleted silicon on insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 × 20 nm(2) is obtained by employing electron beam lithography for active and gate level patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a current spin density functional theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronic and quantum variable based devices.
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Few electron limit of n-type metal oxide semiconductor single electron transistors
Nanotechnology, 2012Co-Authors: Enrico Prati, Matteo Belli, Matthias Ruoff, Dharmraj Kotekar-patil, Marco Michielis, Simone Cocco, David A. Wharam, Marco Fanciulli, Dieter P. Kern, Jan VerduijnAbstract:We report electronic transport on n-type silicon Single Electron Transistors (SETs) fabricated in Complementary Metal Oxide Semiconductor (CMOS) technology. The n-MOSSETs are built within a pre-industrial Fully Depleted Silicon On Insulator (FDSOI) technology with a silicon thickness down to 10 nm on 200 mm wafers. The nominal Channel Size of 20 $\times$ 20 nm$^{2}$ is obtained by employing electron beam lithography for active and gate levels patterning. The Coulomb blockade stability diagram is precisely resolved at 4.2 K and it exhibits large addition energies of tens of meV. The confinement of the electrons in the quantum dot has been modeled by using a Current Spin Density Functional Theory (CS-DFT) method. CMOS technology enables massive production of SETs for ultimate nanoelectronics and quantum variables based devices.
Guangwen Chen - One of the best experts on this subject based on the ideXlab platform.
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ultrasound assisted gas liquid mass transfer process in microreactors the influence of surfactant Channel Size and ultrasound frequency
Chemical Engineering Journal, 2021Co-Authors: Zhengya Dong, Shuainan Zhao, Qiang Zhang, Zhikai Liu, Guangwen ChenAbstract:Abstract Ultrasound effect on the hydrodynamics and mass transfer behavior of gas–liquid Taylor flow is studied in ultrasonic microreactors with different frequencies (20, 28, 40 kHz) and Channel dimensions (0.5 × 0.5, 1.0 × 1.0, 1.5 × 1.5, 2.0 × 2.0 mm2). Upon ultrasound irradiation, intense bubble oscillation is excited on the slug bubble, accompanied by cavitation microstreaming vortices around it. The amplitude of bubble oscillation decreases with the decrease of Channel dimension as a result of the confinement effect. Channel dimension of 1.0 × 1.0 mm2 is considered as the critical dimension above which the confinement effect would be eliminated. More intensive bubble oscillation and cavitation microstreaming are observed at lower ultrasound frequency, where more significant mass transfer enhancement is also observed. At frequency of 20 kHz, the overall volumetric mass transfer coefficient is improved by 22 times at the power density of 0.14 W/mL. Adding surfactant (SDS) in the liquid increases the amplitude of bubble oscillation due to the decrease of interfacial tension. Such an increase in the oscillation amplitude enlarges the specific surface area, leading to an increase in the overall volumetric mass transfer coefficient with the increase of surfactant concentration. The detailed effect that how gas–liquid mass transfer would be enhanced by ultrasound is quantified by a mass transfer model, which could predict both the liquid side mass transfer coefficient and the specific surface area satisfactorily.
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acoustic cavitation and ultrasound assisted nitration process in ultrasonic microreactors the effects of Channel dimension solvent properties and temperature
Chemical Engineering Journal, 2019Co-Authors: Shuainan Zhao, Guangwen Chen, Quan YuanAbstract:Abstract Experimental studies on acoustic cavitation and ultrasound-assisted nitration reaction were systematically investigated in two laboratory-built ultrasonic microreactors by tuning the microChannel dimension, solvent properties and temperature. Under ultrasound irradiation, acoustic cavitation microbubbles were generated and underwent violent oscillation in microChannel. With the decrease of Channel Size, acoustic cavitation was largely confined, and Channel Size 1 × 1 mm2 was recognized as the critical Size to eliminate the confinement effect. Acoustic cavitation was also highly dependent on the properties of sonicated liquids. The onset of surface wave oscillation on gas bubble was obviously promoted with decreasing solvent viscosity and surface tension. Additionally, ultrasound-assisted nitration process of toluene was studied in a temperature-controlled ultrasonic microreactor. The effects of Channel Size as well as liquid properties on ultrasound intensification agreed well with the finding in cavitation research. Under ultrasound power 50 W, toluene conversion was enhanced by 9.9%–36.3% utilizing 50 vol.% ethylene glycol aqueous solution as ultrasound propagation medium, exhibiting ultrasound applicability on intensifying fast reaction processes in microreactors.
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hydrodynamics and mass transfer characteristics of liquid liquid slug flow in microChannels the effects of temperature fluid properties and Channel Size
Chemical Engineering Journal, 2019Co-Authors: Shuainan Zhao, Qi Zhang, Hongchen Liu, Chaoqun Yao, Guangwen ChenAbstract:Abstract Immiscible liquid–liquid flow patterns and mass transfer were investigated in circular PTFE capillaries, with toluene-sulfuric acid, toluene-water and ethyl acetate-water systems. By comparing the slug flow operation range at different temperatures and capillary diameters, the results revealed the roles of inertia and viscous force in the transition from slug flow to droplet flow, and from slug flow to annular flow. A universal flow map based on composite terms of C a C R e C 0.5 and C a D 0.7 R e D 0.5 was proposed to represent the competition between interfacial tension and the inertia/viscous force, which can excellently predict experimental data and literature results with fluid viscosity ranging from 0.85 to 1200 mPa·s. Additionally, the effect of temperature on the dispersed phase slug velocity, specific surface area and mass transfer was investigated and discussed, providing incremental understanding on the flow hydrodynamics and better guidance for optimized reactor design.
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mixing and residence time distribution in ultrasonic microreactors
Aiche Journal, 2017Co-Authors: Zhengya Dong, Shuainan Zhao, Yuchao Zhang, Quan Yuan, Guangwen ChenAbstract:Intensification of liquid mixing was investigated in domestic fabricated ultrasonic microreactors. Under the ultrasonic field, cavitation bubbles were generated, which undergo vigorous translational motion and surface oscillation with different modes (volume, shape oscillation, and transient collapse). These cavitation phenomena induce intensive convective mixing and reduce the mixing time from 24–32 s to 0.2–1.0 s. The mixing performance decreases with the Channel Size, due to the weaker cavitation activity in smaller Channel. The energy efficiency is comparable to that of the conventional T-type and higher than the Y-type and Caterpillar microreactors. Residence time distribution was also measured by a stimulus-response experiment and analyzed with axial dispersion model. Axial dispersion was significantly reduced by the ultrasound-induced radial mixing, leading to the increasing of Bo number with ultrasound power. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1404–1418, 2017